Former 100m world record holder Asafa Powell was given a retroactive 18-month ban for his positive drug test in June, meaning he is not eligible to race until December, according to Jamaican reports.

Powell’s team has begun preparations to appeal it, he said in a statement on his website.

“This ruling is not only unfair, it is patently unjust,” the statement read. “Panels such as these, I understood, were assembled to allow athletes who, consciously or unconsciously come into conflict with the rules of sport, a chance at equitable redemption. Unfortunately, this was not the case.”

The decision was handed down by a Jamaica Anti-Doping Commission disciplinary panel on Thursday.

“This is the 1st time in nearly 12 years of being in the sport and over 150 tests that I have had an adverse finding,” Powell said in the statement. “A stimulant that that is only banned during competition and experts have declared has no performance enhancing effects.

“Sanctions for a stimulant and this kind of infraction usually range from public warnings to a ban of three months, six months in the most extreme cases; I was and am still more than prepared to accept a sanction that is in line with the offense. Instead; 9 months later; what has been handed down is clearly not based on the offense nor the facts surrounding it.”